TimeStep = 0 does not pause Unity Physics simulation (manually stepping physics)

We manually step physics for our product, and one thing I have noticed is that setting the TimeStep = 0 does not fully stop the simulation. Things still move, but much slower.

Here is a snippet of code showing how we step the simulation:

Code (CSharp):

1. using Unity.Entities;
2. using UnityEngine;
3. using UnityEngine.Events;
4.  
5. [DefaultExecutionOrder(-32000)]
6. public class PhysicsTick : MonoBehaviour
7. {
8.     public UnityEvent<float> OnBeforeStepEcsPhysics;
9.  
10.     private FixedStepSimulationSystemGroup fixedStepSimulationSystemGroup;
11.     protected void Start()
12.     {
13.         fixedStepSimulationSystemGroup = World.DefaultGameObjectInjectionWorld.GetOrCreateSystem<FixedStepSimulationSystemGroup>();
14.         fixedStepSimulationSystemGroup.Enabled = false;
15.         fixedStepSimulationSystemGroup.RateManager = new RateUtils.FixedRateSimpleManager(0);
16.     }
17.  
18.     protected void Update()
19.     {
20.         fixedStepSimulationSystemGroup.Timestep = 0;
21.         fixedStepSimulationSystemGroup.Enabled = true;
22.         fixedStepSimulationSystemGroup.Update();
23.         fixedStepSimulationSystemGroup.Enabled = false;
24.     }
25. }
26.  

You can put this MonoBehaviour onto a game object in the ApplyImpulse physics sample, and when you play, you will notice that the objects are still moving/simulating, just very slowly. Is there any way to get the simulation to completely pause with TimeStep alone or will we need to just disable the StepPhysicsWorld system?